Problem with slider in mootools 1.2

[andy72]

Hi @all,

i have a problem with the Slider in mootools 1.2...
My script is part of a image galerie, so the slider is to zoom the
image to its original size.
The Problem: i can not set dynamic the maximum step value in my
slider :(

code:
var numSteps = 0;

myFunction() {
  var img = $("currentImage");
  numSteps = parseInt(img.width);
}

var mySlider = new Slider({
  steps: numSteps,
  onChange: function(step) {
    doWhatEver(step);
  }
}).set(0);

very thanks for help
Andy